Download AP Biology Unit 1- The Chemistry of Life

AP Biology Unit 1--Chemistry of Life-- Study Guide
Chapters 2, 3, & 6
1. Basic Chemistry
2. Water
3. Organic molecules in organisms
4. Enzymes
Key Terms
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Hydrogen bond
Cohesion
Adhesion
Capillary action
Heat capacity
Carbohydrate
Hydrolysis
Starch
Cellulose
Amino acids
Dehydration
synthesis
12. Peptide bond
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
Protein
Lipids
Nucleic acids
Phospholipids
Hydrophilic head
Phosphate
Hydrophobic
tails
Lipid bilayer
Saturated
Unsaturated
exergonic
reaction
24. endergonic
reaction
25. enzyme
26. activation energy
27. enzyme-substrate
complex
28. competitive
inhibitor
29. noncompetitive
inhibitor
30. feedback
inhibition
Recommended Work For Chapters 2 & 3:
1. Concept Checks
2. Testing Your Understanding Levels 1 & 2
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AP Biology Unit 1- The Chemistry of Life
ELEMENTS
Although all of the substances in the universe are chemically diverse, they all have one
thing in common: They’re all made up of elements. Elements, by definition, are
substances that cannot be broken down into simpler substances by chemical means. There
are 92 naturally occurring elements found in nature.
THE ESSENTIAL ELEMENTS OF LIFE
Although there are 92 different elements in the known universe, 99% of all living matter
is made up of just six of them. These are considered the essential elements of life:
Write out the names of the six elements essential to life.
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AP Biology Unit 1—Chemistry of Life
C
H
O
N
P
S
SUBATOMIC PARTICLES
If you break down an element into smaller pieces, you’ll eventually come to an atom.
Define atom:_____________________________________________________________
Atoms are the building blocks of the physical world. Within atoms, there are even
smaller subatomic particles called protons, neutrons, and electrons.
Draw and label a diagram of a carbon atom, include the subatomic particles:
In your own words describe the atomic structure of an atom and the interactions of the
subatomic particles.
COMPOUNDS
Define compound:
You’ll sometimes find that a compound has different properties from those of its
elements. For instance, hydrogen and oxygen exist in nature as gases. Yet when they
combine to make water, they often pass into a liquid state. When hydrogen atoms get
together with oxygen atoms to form water, we’ve got a chemical reaction:
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AP Biology Unit 1—Chemistry of Life
Write out the chemical reaction for the above reaction: Label the reactants and the
products.
The atoms of a compound are held together by chemical bonds, which may be ionic
bonds, covalent bonds, or hydrogen bonds.
Define the following terms and give examples of each:
a. ionic bond
b. covalent bond
c. nonpolar covalent bond
d. polar covalent bond
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AP Biology Unit 1—Chemistry of Life
WATER: THE VERSATILE MOLECULE
One of the most important substances in nature is water. Did you know 70% of your body
weight consists of water? Water is considered a unique molecule because it plays an
important role in chemical reactions.
Draw and label a diagram of water:
Explain why water is a polar molecule, include partial charges both negative and
positive.
Define hydrogen bond and is it a strong or weak bond?
Draw and label a diagram of six water molecules engaging in hydrogen bonds. Hint:
start with a central water molecule and work outward.
Hydrogen bonds are not actually bonds, but strong intermolecular forces that act in a
bond-like way. It’s this property that makes water a great solvent- it can dissolve many
kinds of substances. The hydrogen bonds that hold water molecules contribute to a
number of special properties:
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AP Biology Unit 1—Chemistry of Life
Describe and explain the significance to life, the following properties that water has do to
hydrogen bonding:
a. cohesive forces
b. cohesion
c. adhesion
d. capillary action
e. heat capacity
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AP Biology Unit 1—Chemistry of Life
THE ACID TEST
Water is important because most reactions occur in watery solutions. Reactions are also
influenced by whether the solution in which they occur is acidic, basic, or neutral.
What makes a solution acidic or basic?
What is the difference between acidity and alkalinity?
The acidity and alkalinity of a solution can be measured using a pH scale.
Draw and label a pH scale ranging from 0 to 14, include what pH’s are considered
acids, what pH’s are considered bases, what pH is neutral, and where the following
would fall on the pH scale: concentrated nitric acid, stomach acid, lemon juice, cola
drinks, vinegar, black coffee, distilled water, blood, seawater, laundry bleach,
ammonia, oven cleaner, and drain cleaner.
ORGANIC MOLECULES
Most of the chemical compounds in living organisms contain a skeleton of carbon atoms.
These molecules are called organic compounds. By contrast, molecules that do not
contain carbon atoms are called inorganic compounds. For example, salt (NaCl) is an
inorganic compound.
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AP Biology Unit 1—Chemistry of Life
Explain why carbon is important for life.
FOUR CLASSES OF ORGANIC COMPOUNDS CENTRAL TO LIFE.
Carbohydrate
Describe a carbohydrate. What is the function of carbohydrates?
What is a monosaccharide? What are the two most common sugars?
Draw the ring form and linear form of glucose.
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AP Biology Unit 1—Chemistry of Life
What is a disaccharide? Draw the reaction of two glucose molecules that combine to
form maltose. (Draw the structures)
What is a dehydration synthesis reaction or a condensation reaction.
What is a hydrolysis? Write out a reaction to demonstrate hydrolysis.
What are polysaccharides? Describe the structure and function of starch, cellulose and
glycogen.
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AP Biology Unit 1—Chemistry of Life
These are important functional group to know.
Complete the following chart of functional groups.
Name of Group
Structural Formula
Examples
Amino (amine)
Methyl (methylated compound)
Carboxyl (carboxylic acid)
Hydroxyl (alcohol)
Carbonyl-Aldehyde
Carbonyl-Keto
Sulfhydryl (thiol)
Phosphate (organic phosphate)
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AP Biology Unit 1—Chemistry of Life
Proteins
Amino acids are organic molecules that serve as building blocks of proteins. They
contain carbon, hydrogen, oxygen, and nitrogen atoms. There are 20 different amino
acids commonly found in proteins. You don’t have to memorize the 20 amino acids. But
you do have to remember that every amino acid has four important parts:
Draw the structure of a typical amino acid and label the four important parts: amino
group, carboxyl group, a central carbon with a hydrogen, and R group.
Draw the structure of the amino acid glycine and phenylalanine. Identify the R groups.
What is a polypeptide?
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AP Biology Unit 1—Chemistry of Life
Proteins can be grouped according to their function. Some major categories follow:
Define the function and give examples of the following types of proteins:
1. Structural proteins
2. Storage proteins
3. Transport proteins
4. Defensive proteins
5. Enzymatic proteins
6. Hormonal proteins
7. Contractile and Motor proteins
8. Receptor proteins
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AP Biology Unit 1—Chemistry of Life
There are four levels that describe the structure of a protein:
Describe each of the following levels of protein structure; include the types of bonds
involved at each level:
1. Primary structure
2. Secondary structure
3. Tertiary structure
4. Quaternary structure
Lipids
Like carbohydrates, lipids consist of carbon, hydrogen, and oxygen atoms, but not in the
1:2:1 ratio typical of carbohydrates. The most common examples of lipids are fats, oils,
phospholipids, and steroids.
Draw the structure of a typical fat consisting of three fatty acids and one glycerol
molecule. This molecule is called a triglyceride.
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AP Biology Unit 1—Chemistry of Life
Explain the difference between saturated fatty acids, monounsaturated fatty acids, and
polyunsaturated fatty acids. Draw the structure of each molecule.
Phospholipids
Draw, label, and describe the structure of a phospholipid. Include the head region, the
tail region, hydrophobic region, and hydrophilic regions.
Steriods
Draw the structure of a typical steroid.
Describe the function of steroids.
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AP Biology Unit 1—Chemistry of Life
Nucleic Acids
Like proteins, nucleic acids contain carbon, hydrogen, oxygen, and nitrogen, but nucleic
acids also contain phosphorus. Nucleic acids are molecules that are made up of simple
unit called nucleotides. You need to know about two kinds of nucleic acids:
deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
List the four bases of DNA and identify the two purines and the two pyrimidines.
List the four bases of RNA and identify the two purines and the two pyrimidines.
Draw the structure of a nucleotide of DNA with the base adenine.
Draw the structure of a nucleotide of RNA with the base cytosine.
The Energy of Life: An Introduction to Metabolism
Chemical reactions that occur in biological systems are referred to as metabolism.
Metabolism includes catabolism, anabolism, and the transferring of energy from one
substance to another. An organism’s metabolism transforms matter and energy and is
subject to the laws of thermodynamics.
Define Catabolism:
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AP Biology Unit 1—Chemistry of Life
Define Anabolism:
The free-energy change of a reaction tells us whether or not the reaction occurs
spontaneously.
Define free energy:
What is the symbol for a change in free energy?__________________
Define an exergonic reaction and is ∆G negative or positive?
Define an endergonic reaction and is ∆G negative or positive?
ATP powers cellular work by coupling exergonic reactions to endergonic reactions. A
key feature in the way cells manage their energy resources to do work is energy
coupling, the use of an exergonic process to drive an endergonic one. The primary source
of energy for cells in energy coupling is ATP (adenosine triphosphate).
Draw the structure of ATP and the hydrolysis reaction of ATP to ADP.
Describe the role of ATP and this hydrolysis reaction in metabolic reactions.
Enzymes speed up metabolic reactions by lowering energy barriers.
Define catalyst, enzyme, and activation energy. How are they related?
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AP Biology Unit 1—Chemistry of Life
Draw a diagram that graphically depicts how enzymes function. Include free energy,
progress of the reaction, and the reaction rate with and without an enzyme.
Describe the function of enzymes, include the terms substrate, induced-fit model, active
site. Are enzymes changed as a result of a reaction? What affects the efficiency of an
enzyme?
The activity of an enzyme can be affected by several factors.
Environmental factors affect enzyme activity.

Describe how pH affects enzyme activity, and then draw a graph to illustrate this
affect.
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AP Biology Unit 1—Chemistry of Life

Describe how temperature affects enzyme activity, and then draw a graph to
illustrate this affect.
Describe the role of cofactors in chemical reactions, include coenzymes and inorganic
cofactors.
How do living systems regulate chemical reactions? How do they know when to start a
reaction and when to shut it off? One way of regulating a reaction is by regulating its
enzyme. Here are four common ways in which this is done:
Describe how allosteric enzymes work, include allosteric effector, allosteric activator,
allosteric inhibitor, and feedback inhibitor.
Describe competitive inhibition.
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AP Biology Unit 1—Chemistry of Life
Describe noncompetitor inhibitor.
Regulation of enzyme activity helps control metabolism.
Describe Feedback Inhibition. Give two examples for negative feedback.
Grid-In Questions
1. If nine molecules of a monosaccharide with the formula C6H12O6 are assembled to
produce a complex carbohydrate, how many atoms of hydrogen will be in the
final polymer?
Answer:___________
2. Compare the number of H+ ions in a solution with a pH of 2 to a solution with a
pH of 6. If appropriate, include a negative sign in your answer.
Answer:___________
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AP Biology Unit 1—Chemistry of Life
Unit 1 Essay #1
The selectively permeable plasma membrane is composed of phospholipids and proteins, which allow
for its unique functions.
(a) Describe the structure and properties of phospholipids and explain the important roles of
phospholipids in the plasma membrane.
(b) Predict how the normal function of the plasma membrane would be altered if all
phospholipids were saturated, resulting in fatty acid tails without kinks or bends. Explain
the effect this would have on plants located in very cold regions.
(c) Proteins are an important component of the cell membrane. Describe two specific functions
of proteins in the membrane.
(d) Explain the role of each type of protein you selected for part (c) based on the structure and
properties of a protein.
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AP Biology Unit 1—Chemistry of Life
Unit 1 Essay #2
Describe why water is an ideal medium for living things. Explain two properties of water and their
significance to life.
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AP Biology Unit 1—Chemistry of Life
Unit 1 Essay #3
Proteins are complex molecules important to the function of every living organism, and their
chemical properties make them susceptible to conditions in the environment.
(a) Discuss the chemical composition of proteins and the chemical reactions involved in protein
synthesis.
(b) Discuss protein structure and the structure and function of proteins in relation to
environmental factors.
(c) Discuss the role of proteins in the intracellular exchange of information.
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AP Biology Unit 1—Chemistry of Life
Unit 1 Essay #4
When you hard-boil an egg, the clear liquid part surrounding the yolk becomes white and solid.
Describe, in detail, why this happens.
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AP Biology Unit 1—Chemistry of Life
Unit 1 Essay #5
Vertebrate hormones travel through the bloodstream to reach their cells.
Hormones can be a variety of kinds of molecules. Insulin is a hormone that is
protein derivative and testosterone is a steroid molecule.
(a) Describe the structure of a protein hormone and give one more example.
(b) Describe the structure of a steroid hormone and give one more example.
(c) Compare and contrast the response to protein hormones and steroid
hormones. Use specific hormones as examples. These hormones can be ones
that are mentioned or provided or different hormones.
(d) Describe what happens on the target cell when the hormone reaches its
surface.
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